<template>
    <!--banner轮播-->
    <div class="swiper-container" ref="Swiper">
      <div class="swiper-wrapper">
        <div class="swiper-slide" v-for="item in swiperData" :key="item.id">
          <img :src="item.imgUrl" />
        </div>
      </div>
      <!-- 如果需要分页器 -->
      <div class="swiper-pagination"></div>
  
      <!-- 如果需要导航按钮 -->
      <div class="swiper-button-prev"></div>
      <div class="swiper-button-next"></div>
    </div>
  </template>
  
  <script>
  import Swiper from "swiper";
  import "swiper/css/swiper.min.css";
  export default {
    name: "Swiper",
    props: ["swiperData"],
    watch: {
      swiperData: {
        immediate: true,
        handler() {
          //只要数据更新就立马执行实例化Swiper,但是数据更新之后,DOM的更新也是需要过程的,所以此时Swiper仍然没有拿到完整的DOM,所以还是无效
          //我们应该把激活Swiper的代码放在 $nextTick的回调函数中
          //$nextTick将回调延迟到下次 DOM 更新循环之后执行。在修改数据之后立即使用它，然后等待 DOM 更新
          this.$nextTick(() => {
            new Swiper(this.$refs.Swiper, {
              direction: "horizontal", // 垂直切换选项
              loop: true, // 循环模式选项
  
              // 如果需要分页器
              pagination: {
                el: ".swiper-pagination",
              },
  
              // 如果需要前进后退按钮
              navigation: {
                nextEl: ".swiper-button-next",
                prevEl: ".swiper-button-prev",
              },
            });
          });
        },
      },
    },
  };
  </script>
  
  <style></style>